Study of in vitro and in vivo dissolution of theophylline from film-coated pellets.

Tests were performed on the influence of polymer coating films on the rates and the extents of in vitro and in vivo liberation of theophylline from pellets. Uncoated and coated pellets were used in the experiments. The coating material was Eudragit L; The film thickness was varied. The in vivo liberation of theophylline was studied in rabbits. The serum level of the released drug measured with a TDX Analyser. No appreciable difference was observed between the uncoated and the coated pellets as concern the maximum release data, but a significant shift was found in t(max) for Eudragit L coated pellets.